In large commercial and residential construction projects, accommodations must be made for utility lines and stormwater run-off management. For example, in commercial building structures, utility lines and cables such as electrical lines, natural gas lines, and communications lines need to be installed in the interior and the exterior of the buildings and connected to local grids and service lines. Inside multi-story commercial buildings, these lines and cables are often routed below floors, above suspended ceilings or within columns and walls inside of buildings. Where routed below floors, architects and civil engineers often have to provide elevated, semi-permanent floor structures to access and route such lines or permanently mount hollow conduits or pipes in the individual concrete floors so lines can initially be installed or future lines routed and serviced.
Further, respecting commercial and residential building structures, stormwater, collection, management and retention structures are of increasing concern due to potential environmental impacts of such construction projects. Exterior stormwater management systems are often below-grade structures, and are used to manage stormwater run-off from impervious surfaces such as roofs, sidewalks, roads, and parking lots. Sub-surface water collection and storage chamber systems can be designed to retain stormwater run-off and allow for a much slower discharge of stormwater effluents. As an example, such systems can be constructed underneath vehicle parking lots and structures, such that the storage chamber system receives water from drain inlets or other structures, and discharge it over time. An example of existing exterior stormwater devices is the Triton Stormwater Solutions chamber management systems.
The design and installation of conventional underground stormwater chamber solutions is challenging due to many factors. For example, as underground systems, the space or footprint of the large and lengthy chambers is restricted by the land owned and available for use by these systems. Where a large rectangular space is not available at a site for parallel orientation of multiple chambers, irregular configurations and less than optimal orientations of the chambers are necessary to maximize the spatial volume to retain and gradually disburse the stormwater or other water run-off.
Further, in some applications, the depth of the excavation defining the void space may be limited, or less than typical, which doesn't allow for traditional stormwater management devices and systems to be installed and provide effective and efficient fluid retention capacity. For example, in high water table areas where stormwater management is required to develop the land, conventional devices will not permit the use of underground systems because their size would extend into the water table which is not acceptable. French drain-style drain system may used in these applications, but typically only have a maximum storage capacity of about 40% of the void space and are limited in excavation depth applications ranging from about 40 inches to 144 inches.
Prior stormwater retention systems also suffered from disadvantages of having to use large amounts of porous material, for example stones in a certain size range, to fill the excavation void space not occupied by the water retention chambers and the interstitial volume spaces between the underground water retention chambers and other water retention structures. The stone greatly reduces the total void space that is available in an excavation for collection and retention of stormwater run-off. It is estimated that the commonly used stone sizes occupy 60-70% of the available void space where installed in prior stormwater retention excavations.
Stone is further expensive to purchase, transport to the jobsite and requires a large storage footprint at the jobsite until it is scheduled for installation in the excavation. Stone is also very heavy and requires large earth moving equipment to move the stone from the transportation trucks to the jobsite storage area on arrival and from the jobsite storage area to the excavation at the scheduled time of installation which could be days or even weeks apart. Typical rental of the large earth moving equipment required for the movement and installation of the stone is a significant expense. If there are unscheduled delays, these installation costs incurred by the use of stone only increase.
There is a need for a robust modular stormwater containment system that provides an interior chamber which can be selectively configured to provide multi-directional stormwater pathways and serve as a stormwater retention chamber for the gradual diffusion of stormwater runoff through the soil column which recharges the aquafer system which in turn replenishes the environment. There is further a need for a shallow or low profile stormwater or fluid retention device and system which maximizes useful fluid management void space for increased water retention capacity and efficient operation. There is further a need to improve on underground stormwater retention systems to improve performance capabilities, system life span and reduce burden and costs.